my 1987 xjs is sputtering intermittingly i found the distributor rotor was trying to come apart and i replaced it the jag ran perfect until i got on the expressway it started to sputter not as bad but some but now thru the city it dies on me sometimes while sputtering this has been a great car to me no real issues i replaced a water pump this year has someone had this problem or could someone give me some advice as what to do im thinking maybe the distributor since the rotor button was coming apart

 

I suggest you start with a new distributor cap to go with the rotor.

Greg

 

+1 to Greg's advice.
If the rotor was coming apart it could have damaged the cap. I always replace cap and rotor together anyway.

 

thanks for the advice i will be looking at the distributor tomorrow and i will replace the cap and rotor this time

 

after taking your advice i took the distributor cap off and to my surprise the rotor button on the cap was burned and deteroirating so i ordered a distributor cap and will put it on and go for a drive this evening i will report prayerfully good news

 

Good luck!

 

Sputtering = misfire. Misfire = Raw gas in cylinder. Raw gas in cylinder = Fire. Your lucky this time.

 

thanks for all the help with the distributor cap car ran beautiful for a little while after i changed the distributor cap didnt get a chance to drive it because it shut off on me and now will not start has never done this i took the distributor cap off and rechecked the firing order the car does not start now unless i unplug the fuel pump i ran strait current to it that was not the problem when i unhook the power from the car it run for a min

 

I'm sorry, but can you clarify this a bit?
You've changed the cap, and it ran good. Now it won't start, and you know it isn't the fuel pump?

 

I put the distributor cap on the car and it ran for say 10 min or so beautifully then it shut off and I could not get it to start again I checked for spark it had good spark so I went to fuel well the fuel pump is pumping fuel fine when I put power to it but I thought maybe I had flooded the car so i unplugged the fuel pump and it started up but it was flooded also when i hook the fuel pump back up it will not start

 

Ok, good spark....good








Are you sayng the pump won't work *unless* you put power to it?








And you determined it was flooded, how? Smell of raw fuel? Wet spark plugs? Black exhaust smoke? Just wondering






If you have excessive fuel pressure (from a faulty fuel pressure regulator) you could get flooding. Or, if there was an electrical problem (such as a grounded-out injection harness) causing the injectors to stay open, you could get flooding.

In either case disconnecting the fuel pump would help relieve the problem temporarily, as you'd no longer be pumping fuel into the cylinders and the engine would run for a few moments....burning off the fuel that had already been dumped into the cylinders.

Cheers
DD

 

I know it is flooding because I removed a spark plug and it is very wet I don't understand what happened I just changed the distributor cap I looked to see if I knocked something loose nothing that i could see is there anyone that can help me with this problem I can't seem to figure it out I have been working on it for two days now

 

OK, wet spark plug = raw fuel = too much to ignite = dead engine = what you got.

How, mmmm, fuel pressure regulator has failed, and you 2 of them. The LH unit is the ACTUAL regulator, and the RH unit is a "pulse damper". BOTH have a small vac hose going directly into each inlet manifold. SOooooo, remove those small hoses, have a look, there may be WET fuel visible, in one or both, if so, problem found, if not, leave those hoses OFF, and turn ON the ignition (fuel pump pumps), DO NOT start the engine, and note if fuel "dribbles" out of one or both spigots, if so, there is your problem.

I cannot see the relevence to changing the cap and rotor, but these regulators do just fail, coz they can.

 

Plugs can also be wet because there is no spark. Maybe you disturbed the shielded wire?

 

Good advice but I'll just add that absence of raw fuel doesn't prove that a pressure regulator is OK.

Cheers
DD

 

If the plugs are really soaked, it may not want to start or run either. So new plugs might be in order!

 

Car starts then cuts right off with fuel pump unplugged. With it plugged in car will not start. Pulled one plug, not wet. Was running prior to changing cap and rotor.

 

Coolant temp sensor?

 

thanks everyone for the advice i feel like family here with all the support but i still have no start i checked the fuel regulators they seem to be good the fuel pressure at the fuel rail is 36 so that seems fine i checked to see if any grounds were bad to no avail i feel defeated LOL never been this stumped on a vehicle any more advice as to what to do ?????????????????????????????????????????????????? ??????????????????????????????????????????

 

Mmmmmm.

Back to basics, skip what you have checked.

Has it got spark, a spare spark plug in the end of any easy to get at plug lead will determine this.

Are the injectors "clicking", if not, then the shielded wire is highly suspect. It also informs the ECU that there is ignition pulse present, so injection activity is maintained.

The CTS (coolant temp sensor) in the rear of the LH thermostat base is required for engine running, and the wires inside the plug are flimsy at best, and break very often, and the engine is dead without this sensor giving its reading to the ECU.

The module inside the ignition amp may be hissy, it controls spark (suggestion 1), and also the signal to that shielded wire.

I am still trying to get my head around the "starts without fuel pump plugged in, and zero with it plugged in", as it basically makes no sense at the moment. It must be getting fuel from somewhere to actually "fire". Thinking as I type on that. The "main relay" in the RED socket in the boot, switches the ECU "ON", and the fuel pump relay "ON", so if the fuel pump relay/fuel pump is suspect, the main relay may be switching itself OFF, due to that issue, then with the pump unplugged, the fault is not sensed, so the "main relay" stays "ON", so the ECU is active, as is the EFI system, so engine "fire" occurs, plug the pump in, and the fault returns, so the relay cuts off, as does the ECU and the EFI system, hence a dead engine. If that makes sense.

All this still does not get my head around the rotor and cap replacement causing it???????.